Various low-vision devices are available to improve the eyesight of people with macular degeneration. For example, there are a variety of magnifiers that enlarge print to make it easier to read. Such magnifiers include spectacles, telescopes, handheld or stand-alone magnifying glasses, and closed-circuit television devices.
A number of telescopic devices have been developed for mounting on spectacle frames or embedding in spectacle lenses. For example, miniature Galilean or Keplerian telescopes may be fitted into bores made through the spectacle lenses (typically in the upper part of the lenses). As another example, U.S. Pat. No. 5,680,194 describes a periscopic telemicroscope for spectacles, which mounts over the periphery of one of the spectacle lenses. As yet another example, U.S. Pat. No. 6,972,903 describes a vision assisting apparatus that includes a casing for forming an inversely U-shaped optical path, with an attaching structure for attaching the casing to a wearer so that the light exit is positioned close to an eye of the wearer.
An alternative type of arrangement is suggested by U.S. Pat. No. 6,775,060, which describes a bioptic telescope that is at least partially embedded in a spectacle lens. In one embodiment, the telescope includes a plurality of optical elements defining an optical path for viewing an object, such that at least a portion of the optical path is located within the spectacle lens in a plane substantially orthogonal to the vision axis.